Current investigations are being conducted on the events leading to the formation of several types of cataracts. Hereditary cataract formation is being studied in two strains of mice developed in our laboratory. Both develop osmotic cataracts; however, subtle significant differences suggest different modes of cataract formation in these studies. Diabetic or sugar cataract formation is also being studied. Initiated by the enzyme aldose reductase, methods for controlling the onset of these cataracts through the regulation of this enzyme are being developed.